Metal panels provide good roofs, but cannot be applied as large sections of a roof due to temperature related buckling, distribution of fasteners, and wind-lift issues. Many attempts to use large-area metal panels have failed for these reasons. Long narrow roof panels, however, have proven successful. A roof structure results by placing a series of elongate narrow panels side-by-side in overlapping and interlocking relation across a roof substrate.
Thus, metal roof panels are from one to one and one-half feet wide and extend vertically along the roof from gutter line to ridge. The depth of panels is typically one to three inches as provided by bending formations for rigidity and by interlocking structures. Each panel has complimentary interlocking structures along its edges. A left edge of a first panel interlocks with an overlapping right edge of a second adjacent panel. A variety of particular configurations and interlocking structures have developed, but the basic method of use is by complimentary interlocking structures along the edges of each elongate roof panel.
In a typical configuration, each panel includes a female structure and a complimentary male structure along respective edges of the elongate panel. At the outermost edge and adjacent the female structure, a series of apertures allow attachment by fasteners therethrough to a roof substrate. This ties-down the "female" side of each panel. The male structure of an adjacent second panel couples, i.e., interlocks by virtue of the complimentary relation to the female structure, to the female structure of the previous panel in the series. This ties-down the "male" side of each panel. Each panel at its "male" side covers the fasteners along the "female" side of the previous panel in the series. Thus, while each panel attaches directly to the roof substrate only at one edge, the other edge interlocks to a previous panel along the fastened edge of that previous panel.
In applying such roofing panels, a worker lays down at one extreme edge of the roof, e.g., the left-most edge, a roof panel and screws it in place including attachment along its right edge. The next panel then lays upon and interlocks at its left edge with the right edge of the first panel. One person works a given planar roof section at a time because, at any given time, there is only one "working edge" available to receive a next panel in the series of panels. The process continues in series until a given section of roof is traversed sideways, e.g., left to right.
A particular problem arises in hip roof applications. More particularly, a hip roof includes four or more planar regions. For each planar region, the outside portions taper in length, i.e., progressively shorter distance between ridge line and gutter line as one approaches the outer-most edges. In applying the metal roof panels as described above, one begins at the left-most edge of a given planar section and works across the roof section. The first panel attached is the shortest panel of the series of panels for that section of roof. One must carefully align this first and very short roof panel as this first panel sets the orientation, i.e., vertical alignment, for all remaining panels across this section of roof. Despite best efforts, many panels are not properly aligned due to small errors at the beginning of the process, i.e., the initial short length panel was crooked, and such errors propagate across the entire planar roof section. Sometimes this results in an unacceptable appearance and requires removal and re-application of roof panels. Such removal often results in damage or sometimes destruction of the roof panels. Furthermore, such removal constitutes unproductive roof construction necessitated by the occasional need to remove panels due to misalignment.
In any construction project, time is of the essence. The faster a job can be completed the more valuable the job is to the customer and to the contractor providing the job. Due to the quality issues and productivity issues presented in constructing metal roofs by means of conventional, elongate, narrow roof panels, it would be desirable to improve metal roof construction in both quality and productivity.